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Date: Thu, 14 Jul 2011 00:21:14 +1000
Subject: Re: What is the difference between PyPy and Python? are there lot of differences?
From: Chris Angelico <rosuav@gmail.com>
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On Thu, Jul 14, 2011 at 12:06 AM, ArrC <justmailnaveen@gmail.com> wrote:
> So, i want to know what are the core diff btw PyPy and Python ?

Python is a language; PyPy is one implementation of that language. The
"classic" implementation of Python is CPython, not to be confused with
Cython; there are a few others as well. If you talk of "installing
Python", it probably means CPython.

> And they also talked about the lack of type check in python.
>
> So, how does it help (strongly typed) in debugging?

Sloppy but brief explanation: Python's variables are typeless; its
objects are strongly typed.

Longer explanation: Every piece of data in Python is an object.
Objects can be referenced by names; one object can have more than one
name pointing to it. Any name can point to any value, which is
somewhat the opposite of "strongly-typed variables" in other
languages. For instance:

a = "Hello"    # a points to or "holds" a string
a = 234    # a now points to an integer
a = 1.0    # a now points to a float
a = [1,2,3]    # a now has a list (array)

In debugging, all you generally care about is "what does this object
point to". I guess whether or not this makes things easier or harder
depends a lot on what sort of bugs you're tracking down.

Hope that helps!

Chris Angelico